Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Suggest dereference of
Box
when inner type is expected
For example: enum Ty { Unit, List(Box<Ty>), } fn foo(x: Ty) -> Ty { match x { Ty::Unit => Ty::Unit, Ty::List(elem) => foo(elem), } } Before, the only suggestion was to rewrap `elem` with `Ty::List`, which is unhelpful and confusing: error[E0308]: mismatched types --> src/test/ui/suggestions/boxed-variant-field.rs:9:31 | 9 | Ty::List(elem) => foo(elem), | ^^^^ | | | expected enum `Ty`, found struct `Box` | help: try using a variant of the expected enum: `Ty::List(elem)` | = note: expected enum `Ty` found struct `Box<Ty>` Now, rustc will first suggest dereferencing the `Box`, which is most likely what the user intended: error[E0308]: mismatched types --> src/test/ui/suggestions/boxed-variant-field.rs:9:31 | 9 | Ty::List(elem) => foo(elem), | ^^^^ expected enum `Ty`, found struct `Box` | = note: expected enum `Ty` found struct `Box<Ty>` help: try dereferencing the `Box` | 9 | Ty::List(elem) => foo(*elem), | + help: try using a variant of the expected enum | 9 | Ty::List(elem) => foo(Ty::List(elem)), | ~~~~~~~~~~~~~~
- Loading branch information